LT-GaAs with high breakdown strength at low temperature for power MISFET applications

1995 ◽  
Vol 24 (7) ◽  
pp. 913-916 ◽  
Author(s):  
K. -M. Lipka ◽  
B. Splingart ◽  
D. Theron ◽  
J. K. Luo ◽  
G. Salmer ◽  
...  
Keyword(s):  
Low Temperature ◽  
Breakdown Strength ◽  
Lt Gaas

Study of Modulation in GaAs Misfets with LT-GaAs as a Gate Insulator

1991 ◽  
Vol 241 ◽  
Author(s):  
L.-W. Yin ◽  
J. Ibbetson ◽  
M. M. Hashemi ◽  
W. Jiang ◽  
S.-Y. Hu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Gaas Layer ◽  
Gate Insulator ◽  
Gate Bias ◽  
Channel Current ◽  
Turn On ◽  
Dc Characteristics ◽  
Low Temperature Gaas ◽  
Channel Separation ◽  
Lt Gaas

ABSTRACTDC characteristics of a GaAs MISFET structure using low-temperature GaAs (LTGaAs) as the gate insulator were investigated. MISFETs with different gate to channel separation (d) were fabricated. The dependence of four important device parameters such as gate-drain breakdown voltage (VBR), channel current at zero gate bias (Idss), transconductance (gm), and gate-drain turn-on voltage (Von) on the gate insulator thickness were analyzed. It was observed that (a) in terms of Idss and gin, the LT-GaAs gate insulator behaves like an undoped regular GaAs layer and (b) in terms of VBR and Von, the LT-GaAs gate insulator behaves as a trap dominated layer.

Laser Quality AlGaAs-GaAs Quantum Wells Grown on Low Temperature GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
Y. Hwang ◽  
D. Zhang ◽  
T. Zhang ◽  
M. Mytych ◽  
R. M. Kolbas
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Quantum Wells ◽  
Barrier Layer ◽  
Molecular Beam ◽  
Optical Quality ◽  
First Order ◽  
Gaas Buffer Layer ◽  
Low Temperature Gaas ◽  
Lt Gaas

ABSTRACTIn this work we demonstrate that photopumped quantum wellheterostructure lasers with excellent optical quality can be grown ontop of a LT GaAs buffer layer by molecular beam epitaxy. Hightemperature thermal annealing of these lasers blue-shifts the laseremission wavelengths but the presence/absence of a LT GaAs layerhad little effect on the overall laser thresholds. Also, to first order itwas not necessary to include an AlAs barrier layer to preventadverse effects (as has been necessary in the gate stack of MESFETs to prevent carrier compensation).

Real-Time Pseudodielectric Function of Low-Temperature-Grown GaAs

2000 ◽  
Vol 618 ◽  
Author(s):  
D.A. Gajewski ◽  
J.E. Guyer ◽  
J.J. Kopanski ◽  
J.G. Pellegrino
Keyword(s):  
Low Temperature ◽  
Real Time ◽  
Diffuse Reflectance Spectroscopy ◽  
High Energy ◽  
Real Time Control ◽  
The Real ◽  
Time Control ◽  
Active Feedback ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

ABSTRACTWe present the real-time pseudodielectric function <ε(E)> of low-temperature-grown GaAs (LT-GaAs) thin films during the growth as a function of growth temperature Tg and thickness. We obtained accurate measurements of the real-time <εc(E)> by using in situspectroscopic ellipsometry (SE) in conjunction with active feedback control of the substrate temperature using diffuse reflectance spectroscopy. We show that for epitaxial LT-GaAs layers, the peak in the imaginary pseudodielectric function <ε2(E)> decreases in amplitude and sharpness systematically with decreasing Tg. We also revealed an abrupt change in <εc(E)> near the critical epitaxial thickness hepi, the value of which decreases with decreasing Tg. Above hepi, the LT-GaAs grows polycrystalline (amorphous) above (below) Tg ∼ 190°C. We also simultaneously monitored the surface roughness and crystallinity by using real-time reflection high-energy electron diffraction (RHEED). These results represent progress in obtaining real-time control over the composition and morphology of LT-GaAs

Multi-Hundred Gigahertz Photodetector Development Using LT GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
Y. Chen ◽  
S. Williamson ◽  
T. Brock ◽  
F. W. Smith ◽  
A. R. Calawa
Keyword(s):  
Low Temperature ◽  
Light Intensity ◽  
Response Time ◽  
Bias Voltage ◽  
Type Detector ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

ABSTRACTWe report on the development of a new, integrable photoconductive-type detector based on low-temperature-grown GaAs. The detector has a response time of 1.2 ps and a 3-dB bandwidth of 375 GHz. The responsivity is 0.1 A/W. This is the fastest photodetector reported to date. We discuss the unique properties of this device, including its performance as functions of both light intensity and bias voltage.

Ultrafast carrier dynamics in LT-GaAs doped with Si delta layers

2017 ◽  
Vol 31 (27) ◽  
pp. 1750195 ◽  
Author(s):  
D. I. Khusyainov ◽  
C. Dekeyser ◽  
A. M. Buryakov ◽  
E. D. Mishina ◽  
G. B. Galiev ◽  
...  
Keyword(s):  
Low Temperature ◽  
Carrier Lifetime ◽  
Carrier Dynamics ◽  
High Resistivity ◽  
Ultrafast Carrier Dynamics ◽  
Si Doping ◽  
Ultrafast Optical ◽  
Donor And Acceptor ◽  
Ultrafast Carrier ◽  
Lt Gaas

We characterized the ultrafast properties of LT-GaAs doped with silicon [Formula: see text]-layers and introduced delta-doping ([Formula: see text]-doping) as efficient method for enhancing the properties of GaAs-based structures which can be useful for terahertz (THz) antenna, ultrafast switches and other high frequency applications. Low temperature grown GaAs (LT-GaAs) became one of the most promising materials for ultrafast optical and THz devices due to its short carrier lifetime and high carrier mobility. Low temperature growth leads to a large number of point defects and an excess of arsenic. Annealing of LT-GaAs creates high resistivity through the formation of As-clusters, which appear due to the excess of arsenic. High resistivity is very important for THz antennas so that voltage can be applied without the risk of breakdown. With [Formula: see text]-Si doping, control of As-clusters is possible, since after annealing, clusters align in the plane where the [Formula: see text]-doping occurs. In this paper, we compare the properties of LT-GaAs-based planar structures with and without [Formula: see text]-Si doping and subsequent annealing. We used pump-probe transient reflectivity as a probe for ultrafast carrier dynamics in LT-GaAs. The results of the experiment were interpreted using the Ortiz model and show that the [Formula: see text]-Si doping increases deep donor and acceptor concentrations and decreases the photoinduced carrier lifetime as compared with LT-GaAs with same growth and annealing temperatures, but without doping.

Spectroscopic Ellipsometric Characterization of Low Temperature GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
X. Gao ◽  
P. G. Snyder ◽  
P. W. Yu ◽  
Y. Q. Zhang ◽  
Z. F. Peng
Keyword(s):  
Low Temperature ◽  
Red Shift ◽  
Strain Effect ◽  
Lorentz Oscillator ◽  
Ellipsometric Characterization ◽  
C 30 ◽  
Low Temperature Gaas ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

AbstractPseudodielectric functions of low temperature grown GaAs (LT GaAs) measured by spectroscopic ellipsometry are presented. The spectral range includes the El (2.92eV) and El+ΔAl (3.13eV) critical point structure of GaAs. A Lorentz-oscillator model was used to fit the dielectric function of LT GaAs for samples with nominal growth temperatures (Tg) varying from 200°C to 580°C. For Tg of 200°C, 30% and 19% broadenings and −0.01 leV and −0.007eV red shifts were found for the El and El+Δl structures respectively, compared with normal GaAs. The red shift can be explained in terms of a strain effect in the LT layer. In annealed LT GaAs the broadening decreased significantly and no red shift was found.

Magnetic Circular Dichroism of Low-Temperature-Grown AlxGa1-xAs

1995 ◽  
Vol 378 ◽  
Author(s):  
A. Prasad ◽  
X. Liu ◽  
P. Stallinga ◽  
E. R. Weber ◽  
A. K. Verma ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Aluminum Content ◽  
Magnetic Circular Dichroism ◽  
Al Content ◽  
Circular Dichroïsm ◽  
Lt Gaas

AbstractWe study magnetic circular dichroism of absorption (MCDA) of LT AlxGa1−xAs as a function of aluminum content. The MCDA spectrum of LT AlxGa1−xAs is distinctly different from the MCDA spectrum of LT GaAs, which has one paramagnetic and one diamagnetic peak at 0.95 eV and 1.18 eV, respectively. As the aluminum content increases, the spectrum of LT AlxGa1−xAs is dominated by a diamagnetic peak similar to the 1.18eV peak of the EL20-like defects in LT GaAs. However, the peak shifts to higher energies as x increases. The photoquenching and temperature dependence of this peak indicates an association with the EL2 defect. The paramagnetic peak observed in LT GaAs also shifts to higher energies but faster and eventually merges with the diamagnetic peak as the Al content increases. The study of the MCDA spectrum of LT AlxGa1−xAs as a function of aluminum content allows a better understanding of the MCDA phenomena of LT AlxGa1−xAs and LT GaAs, as well as the EL2-related transitions in bulk semi-insulating GaAs.

Low Temperature Growth of GaAs on Si Substrates for Ultra-fast Photoconductive Switches

2003 ◽  
Vol 768 ◽  
Author(s):  
Kai Ma ◽  
Ryohei Urata ◽  
David A. B. Miller ◽  
James S. Harris
Keyword(s):  
Low Temperature ◽  
Sampling Technique ◽  
High Energy ◽  
Surface Cleaning ◽  
Ex Situ ◽  
Wafer Surface ◽  
Gaas Film ◽  
Gaas On Si ◽  
Photoconductive Switches ◽  
Lt Gaas

AbstractWe have grown GaAs directly on silicon substrates by molecular beam epitaxy (MBE) at low substrate temperatures (∼250 °C). The silicon wafer surface cleaning and GaAs film growth processes were done at temperatures lower than the Si-Al eutectic temperature, in order to enable monolithic integration of low-temperature-grown-GaAs (LT-GaAs) photoconductive switches with Si-CMOS circuits. In situ reflection high-energy electron diffraction (RHEED), ex situ x-ray diffraction (XRD) and atomic force microscopy (AFM) studies were performed to characterize the LT-GaAs film quality. The film surfaces show less than 1 nm root-mean-square (rms) roughness and the anti-phase domain (APD) density is below the XRD detection limit. Metal-semiconductor-metal (MSM) photoconductive switches were made using this material. A time-resolved electro-optic sampling technique was used to determine the responsivity and speed of the switches. A full-width at half-maximum (FWHM) switching time of ∼2 picoseconds was achieved and the responsivity of switches made from LT-GaAs on Si material was comparable to that of switches made from LT-GaAs on GaAs material.

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